using clang tools within a c program

Hello

I though that libclang was the C interface to clang but It seems that libclang is all C++ and so I have to use C++ compiler and extern my c code?

Best

No, libclang has a C interface. libclang and the whole compiler are implemented in C++ but it does provide a C interface [1].

[1] https://clang.llvm.org/doxygen/group__CINDEX.html